1. Field of the Invention
The present invention generally relates to the area of document processing and electronic publishing system, and more particularly, relates to techniques for designing extensible stylesheets.
2. Description of the Related Art
The Internet is a rapidly growing communication network of interconnected computers around the world. Together, these millions of connected computers form a vast repository of hyperlinked information that is readily accessible by any of the connected computers from anywhere and anytime. With millions of web pages being created and added to this vast repository each day or year, there is a tremendous need to quickly and easily convert documents, such as presentations, data sheets or brochures, into a format presentable to and accessible by other applications or devices on the Internet.
It is well known that a preferable format that is presentable to a web browsing application (e.g. a browser) is in a markup language, such as Hypertext Markup Language (HTML), Extensible Markup Language (XML), Standard Generalized Markup Language (SGML) or Wireless Markup Language (WML). Files or documents that are so composed, edited or managed for web browsing applications are commonly referred to as structured files or documents. Among the structured documents, a content-oriented structured document like XML or SGML is capable of supporting any markup tags from document type definitions (DTD) or schema while a presentation document in HTML or WML can only support a fixed set of markup tags.
The demand for dynamically converting the content-oriented structured documents with proper style transformation for a particular request medium opens a new paradigm for information exchange and storage. For example, contents in a website are stored in XML formats. If a web browser (e.g., Netscape or IE) in a desktop computer requests information form the website, the website is preferably to convert the contents in XML into converted contents in HTML and subsequently sends the converted files back to the browser. If a portable device (e.g. a PDA or internet-enabled cell phone) requests information by a microbrowser from the same website, the website is preferably to convert the contents in XML into converted contents in WML and send the converted files back to the microbrowser. Furthermore, the website can also convert the internal XML into another type of XML so as to exchange information between websites.
One need in the aforementioned example for various publications and information exchange is a proper transformation from XML into various formats.